N-halogenated sulfonic acids and alkali metal salts thereof

ABSTRACT

N-HALOGENTATED COMPOUNDS HAVING THE GENERAL FORMULA   R-SO2-N(-X)-(CH2)3-SO3-M   WHEREIN R IS AN ALKYL, ARYL OR SUBSTITUTED ARYL GROUP, X IS BROMINE OR CHLORINE, AND M IS AN ALKALI METAL, ARE USEFUL AS BLEACHING AGENTS AND AS DISINFECTANTS.

O4-Oe-72 AU 165 EX United b'tates Patent O US. Cl. 260-508 9 Claims ABSTRACT OF THE DISCLOSURE N-halogenated compounds having the general formula R-SOzN-(CH1)3-SO;M

wherein R is an alkyl, aryl or substituted aryl group, X is bromine or chlorine, and M is an alkali metal, are useful as bleaching agents and as disinfectants.

BACKGROUND OF THE INVENTION The use of various N-halo organic compounds as bleaching agents and as disinfectants is known. Compounds which have been suggested for these purposes are, for example, dichloroand dibromo-cyanuric acid and their salts, trichlorocyanuric acid, and 1,3-dichloroand 1,3-dibromo-5, S-dimethylhydantoin. The preferred halo compounds are usually chosen for stability and for usefulnesses solely on the basis of halogen release in solution. These compounds hydrolyze readily in aqueous solution to produce hypochlorite or hypobromiteions which are well known as bleaching agents, and they have advantages over well-known peroxy bleaching agents in that they bleach effectively at low temperatures (below 80 0.).

SUMMARY OF THE INVENTION Applicants have now discovered a novel class of compounds, namely N-chloro and N-bromo compounds of the general formula which are good bleaching agents, and further, are capable of effectively removing stains from fabrics at temperatures under 80 C. Additionally, these compounds exhibit the property of being anti-bacterial agents, thereby making them suitable disinfectants as well.

The novel compounds can be prepared, without difiiculty, by one of several reactions dependent on the type or nature of the starting material used. For example, use of an alkali metal derivative of a sulfonamide as a starting material yields the corresponding novel compound in a simple two-step reaction procedure; on the other hand, use of a N-halo aryl sulfonamide as a starting material yields the corresponding novel compound in a one-step reaction procedure.

The nature of R in the general formula can be widely varied to include, as specific examples, alkyl radicals, aryl radicals, and aryl radicals substituted with alkyl groups or halides. Further, the aryl radical can be mono-nuclear or di-nuclear.

Applicants have also found that these novel bleaching compounds can readily and effectively be used in granular bleaching compositions and, also, in granular detergent compositions, the other constituents of such compositions being known in the art to great detail.

Therefore, it is an object of this invention to provide a novel class of effective bleaching compounds; it is another object to provide novel bleaching agents which may be readily prepared, as is hereinafter described; and, it is a further object to provide novel bleaching compounds which may be effectively used in granular bleaching and/ or detergent compositions.

DESCRIPTION OF THE INVENTION Accordingly, the invention provides N-bromo and N- chloro compounds of the general formula:

RSO N-(CH );-SO;M

wherein R is an alkyl, aryl or substituted aryl radical, X is chlorine or bromine, and M is an alkali metal such as Na, N or Li. Preferably R is an alkyl radical with 1 to 18 carbon atoms, or an unsubstituted monoor di-nuclear aryl radical, or a monoor di-nuclear aryl radical substituted by one or more electron-donating or electron-withdrawing groups which groups, if alkyl, contain 1 to 14 carbon atoms. Examples of suitable electron-donating groups include, but are not limited to, the following: nalkyl, sec-alkyl, iso-alkyl, and tort-alkyl groups of from 1 to 14 carbon atoms; C H and substituted derivatives (e.g., OCH Examples of suitable electron-withdrawing groups include, but are not limited to, the following:

NO -X (where X=bromine and chlorine); COR; SO H; CN; and, -N(CH The new compounds can be prepared by (l) reacting the alkali metal derivative of a sulfonamide with 1,3-propane-sultone and then (2) reacting the intermediate compound so formed with a solution of hydrochlorous or hypobromous acid according to the following equations:

wherein R and X have the meanings given above.

An alternative method of preparation of the compounds in which R is an aryl or substituted aryl radical, which avoids use of organic solvents, is to react the sodium salt of an N-chloroor N-bromo-aryl, or substituted-aryl, sulfonamide having the general formula RSOz-N--Na [X=chlorine or bromine] with propane sultone in aqueous solution; R can be the simple benzene radical or a benzene radical substituted, for example, with a chloride ion or a methyl group.

The N-bromo-compounds may also be made by reacting the appropriate novel N-chloro-compound with bromide ion.

The following examples serve to illustrate the invention herein and do not limit it. Additional examples, within the scope of this invention, will be apparent to those skilled in the art. In all examples, any percentages given therein are by weight, unless otherwise stated.

EXAMPLE I Preparation of sodium N-chloro-N-(benzenesulfonyl)- 3-aminopropan-l-sulfonate 71 g. of benzenesulfonamide were dissolved in methanol, and a solution of sodium methoxide (from 3.63 g. of sodium) in methanol was added, giving a molar ratio of sulfonamide to sodium methoxide of substantially 3:1. The mixture was evaporated to dryness, and the solid residue was suspended in 600 ml. of toluene. The suspension was dried by distilling off 50 ml. of toluene; 21.1 g. of 1,3-propanesultone was added, giving a molar ratio of sodium benzenesulfonamide to 1,3-propanesultone of substantially 1:1. The mixture was boiled under reflux for four hours and was then allowed to stand overnight. The solid product was filtered off and dissolved in water. The aqueous solution was neutralized with sulfuric acid and evaporated to dryness. The residue was washed with acetone and then dissolved in a boiling ethanol/water (95/5 v./v.) mixture. On cooling and filtering, 23 g. of sodium N-(benzenesulfonyl)-3-aminopropan-l-sulfonate were recovered.

This compound was dissolved in 500 ml. of 0.22 M hypochlorous acid solution and allowed to stand for 30 minutes. The solution was evaporated to 50 ml. and cooled. The crystalline precipitate was filtered off and dried to yield 22.5 g. of sodium N-chloro-N-(benzenesulfonyl)-3- aminopropan-l-sulfonate monohydrate.

EXAMPLE II Preparation of sodium N-chloro-N-(dodecanesulfonyl)- B-aminopropan-l-sulfonate Dodecanesulfonamide (14.8 g.) was treated with sodium methoxide (from 0.46 gm. sodium, giving a ratio of sulphonamide to sodium methoxide of substantially 3:1) and then with 1,3-propanesultone (2.6 g.) as described in Example 1. On cooling, the gelatinous mass was stirred with acetone (200 ml.), and the product was filtered. Recrystallization from 95% ethanol gave 6 g. of sodium N-(dodecanesulfonyl)-3-aminopropan-1-sulfonate.

1.6 g. of this intermediate compound-i.e., sodium N- (dodecanesulfonyl)-3-aminopropan 1 sulfonate, having the general formula of RSO NH-(CI-I SO M wherein R is the dodecyl radical-were dissolved in hot water (25 ml.), and the solution was added dropwise into 20.5 ml. of 0.32 M hypochlorous acid. The mixture was stirred at room temperature for 10 minutes and cooled. Filtration and drying gave 1.5 g. of sodium N-chloro-N- (dodecanesulfonyl)-3-aminopropan-l-sulfonate.

When R is aryl or substituted aryl, the said intermediate compound (for reaction with hypochlorous or hypobromous acid) can also be made by reacting alkali metal 3-aminopropan-l-sulfonate with an aromatic sulfonyl chloride of the general formula RSO Cl, wherein R is an aromatic or substituted aromatic radical as described above.

EXAMPLE III Preparation of sodium N-chloro-N-(p-toluenesulfonyl) 3-aminopropan-1-sulfonate 1,3-propanesultone (10 g.) was added dropwise to aqueous ammonium hydroxide (200 ml., d. 0.88). The solution was stirred at room temperature for 30 minutes, heated on a steam bath for 1 hour, and evaporated to dryness.

The crystalline residue (11.1 g.) was dissolved in aqueous sodium hydroxide (6.25 g. in 100 ml.), and the solution was concentrated in vacuo to evaporate liberated ammonia. p-Toluenesulfonyl chloride (12.6 g.) was added, and the mixture was stirred at 65-75 C. for 2 hours until it had become homogeneous. This solution was neutralized and evaporated to dryness; the residue was extracted with boiling ethanol-water (9:1 v./v.). Evaporation of the extract gave sodium N-(p-toluenesulfonyl)-3-aminopropan-l-sulfonate (20.5 g.).

This material was dissolved in aqueous hypochlorous acid (380 ml.; 0.21 M). After 30 minutes the solution was concentrated in vacuo and cooled. The crystalline mass (17 g.) was filtered, dried and found to consist of sodium N chloro-N-(p-toluenesulfonyl)-3-aminopropan-l-sulfonate.

4 EXAMPLE 1v Preparation of sodium N-bromo-N-(ptoluenesulfonyl)- 3-aminopropan-l-sulfonate Propanesultone (10 g.) was added dropwise to aqueous ammonium hydroxide (200 ml., d. 0.88). The solution was stirred at room temperature for 30 minutes, heated on a steam bath for 1 hour and evaporated to dryness.

The crystalline residue (11 g.) was dissolved in aqueous sodium hydroxide (6.25 g. in 100 ml.), and the solution was concentrated in vacuo to evaporate liberated ammonia. p-Toluenesulfonyl chloride (12.6 g.) was added and the mixture stirred at 65-75" C. for 2 hours, until it became homogeneous. This solution was neutralized and evaporated to dryness, and the residue was extracted with boiling acetone-water (:5; m1.). Cooling of the extract, followed by the addition of ethanol caused precipitation of sodium N-(p-toluenesulfonyl)-3-arninopropan-1- sulfonate (15 g.) which was filtered and dried.

This material was dissolved in hypobromous acid (166 ml.), 0.29 M), and after 15 minutes the solution Was concentrated and cooled. The highly crystalline N-bromo-N- (p-toluenesulfonyl) 3-aminopropan-l-sulfonate 10.2 g.) was filtered and dried.

EXAMPLE V 10 g. of chloramine T (sodium N-chloro-p-toluenesulfonamide trihydrate) was dissolved in the minimum necessary quantity of water at 60 C.; 4.78 g. of 1,3-propanesultone were added, and the mixture was stirred for 30 minutes. On cooling to room temperature, a crystalline precipitate was formed which was filtered off and dried, providing 9 g. of sodium N-chloro-N-p-toluenesulfonyl)- 3-aminopropan-l-sulfonate monohydrate.

EXAMPLE VI When molecular equivalent amounts of the sodium derivatives of N-chlorobenzene sulfonamide, or N-chlorop-chlorobenzenesulfonamidc, are substituted for the sodium N-chlorotoluenesulfonamide of Example V, the corresponding compounds in which R is C 11 and ClC H are obtained.

Bleach tests were carried out on test pieces of teastained cotton cloth in 18 hard water at 50 C., the water containing 0.2% sodium tripolyphosphate and an amount of bleaching agent sulficient to supply 35 parts per million available chlorine in the bleach liquor; these tests showed that the new N-chloro compounds bleach as effectively as sodium hypochlorite.

The term available chlorine," as used herein, refers to the amount of molecular chlorine (C1,) having equal bleaching power. Since one atom of active chlorine in these N-chloro compounds, and in hypochlorites, has the same activity as one molecule of molecular chlorine (i.e. two atoms), the percentage available chlorine" stated, by weight, is double the weight percentage of reactive chlorine in the molecule. Thus, sodium N-chloro-N-(benzene sulfonyl) 3-aminopropan-l-s'ulfonate monohydrate, having the formula C,H SO,N(Cl)(CH,);,SO Na-H;O, contains 10% actual chlorine by weight, expressed as 20% available chlorine."

The new N-chloro and N-bromo compounds of this invention are suitable for use in the formulation of granular bleaching and detergent compositions and can be conveniently mixed with water-soluble inorganic and organic alkaline salts or with water-soluble organic detergent compounds, or with both.

Water-soluble alkaline inorganic salts which are suitable for use in conjunction with these new compounds are alkali metal carbonates, borates, phosphates, polyphosphates, bicarbonate, silicates, and sulfates. Specific examples include sodium and potassium pyrophosphate and tripolyphosphate, disodium orthophosphate, sodium and potassium hexametaphosphates, trisodium orthophosphate, sodium and potassium carbonate and bicarbonates,

sodium sesquicarbonate, sodium and potassium perborates and tetraborates, and various sodium silicates. Other inorganic alkaline, neutral or acidic salts may be included as fillers or for processing reasons. The corresponding salts of other alkali metals may be substituted for part or all of the sodium salts. Particularly suitable salts are sodium pyrophosphate and sodium tripolyphosphate, sodium bicarbonate, and disodium orthophosphate.

Examples of suitable organic alkaline builder salts are: (1) water-soluble aminopolyacetates, e.g., sodium and potassium, ethylenediaminetetracetates, nitrilotriacetates and N-(2-hydroxyethyl)-nitrilo diacetates; (2) watersoluble salts of phytic acid, e.g., sodium and potassium phytates (see US. Pat. 2,739,942); (3) water-soluble polyphosphonates, including specifically, sodium, potassium and lithium salts of (a) ethane-Lhydroxy-Ll-diphosphonic acid, (b) methylene diphosphonic acid, and (c) ethane-1,1,2-triphosphonic acid; other examples include alkali metal salts of ethane2-carboxy-1,l-diphosphonic acid, hydroxymethanediphosphonic acid, carbonyl diphosphonic acid, ethane-l-hydroxy 1,1,2 triphosphonic, acid ethane-Z-hydroxy-1,1,2-triphosphonic acid, propane-1,1,3, 3 tetraphosphonic acid, propane-1,l,2,3-tetraphosphonic acid, and propane-l,2,2,3-tetraphosphonic acid; (4) watersoluble salts of polycarboxylate polymers and copolymers as described in the patent of Francis L. Diehl, US. 3,308,067 issued Mar. 7, 1967, e.g. itaconic acid, aconitic acid, maleic acid, citraconic acid, mesaconic acid, sumaric acid, methylene malonic acid, and copolymers with themselves and other compatible monomers such as ethylene.

Examples of water-soluble detergent compounds which can be used in the bleaching compositions of this invention include, but are not limited to, the following:

(a) anionic synthetic detergents, as represented by sodium alkyl sulfates, sodium or potassium alkyl-benzenesulfonates, sodium alkylglycerylethersulfonates, and others;

(b) nonionic synthetic detergents, as represented :by polyethylene oxide condensates of alkylphenols; condensation products of aliphatic alcohols of 8 to 18 carbon atoms with ethylene oxide; long chain tertiary amine oxides corresponding to the general formula R R R N- O, wherein R is an alkyl radical of about 8 to 18 carbon atoms with R and R being methyl or ethyl radicals; long chain tertiary phosphine oxides corresponding to the general formula R R R P 0, wherein R is an alkyl, alkenyl or monohydroxyalkyl radical of about to 18 carbon atoms with R and R being alkyl or monohydroxyalkyl groups of l to 3 carbon atoms;

(c) ampholytic synthetic detergents, as represented by the derivatives of aliphatic amines which contain about 8 to 18 carbon atoms and an anionic water solubilizing group (e.g., carboxy, sulfo, sulfate); and,

(d) Zwitterionic synthetic detergents, represented :by

derivatives of aliphatic quaternary ammonium com- The anionic, nonionic, ampholytic, and Zwitterionic detergents may be used singly or in combination together with the present invention. With regard to these detergents, a more complete disclosure may be found in Francis Diehl, US. Pat. 3,213,030, issued Oct. 19, 1965, lines 53 to of column 3, lines 1 to 75 of column 4, and lines 1 to 30 of column 5, and said disclosure is hereby incorporated by reference hereinto.

In granular bleaching compositions, the N-chloro or N- bromo compound may constitute up to or more by weight of the total composition, or it may constitute less than 1% of the total composition; the balance comprises a water-soluble alkaline salt. Generally, a N-chloro or N- bromo compound is included in an amount which provides from 0.5 to 8%, preferably about 4%, by weight of available chlorine in the composition, or, on a corresponding molar basis, from about 1 to 18%, preferably about 9%,

6 of active bromine. A detergent compound, if employed, usually constitutes up to 25% by weight of the composition, preferably 1% to 10%. The pH of such bleaching compositions (as measured in a 1% solution of the composition) is generally in the range 7 to 11, preferably 8.5 to 10.5.

EXAMPLE VII Salt NaHCO; NarP Om N84P2Q7 N13200:

Approximate pH 8. 6 9. 3 9. 7 10. 7 Percent stain removal. 45. 5 60 69 70 Detergent compositions, in which a novel compound of the invention herein is a component, also comprise both a water-soluble organic detergent and a water-soluble inorganic or organic alkaline builder salt. In such compositions, the novel compounds herein can be present in an amount ranging from 0.5% to 25 The amount of detergent can. range, from about 1% to about 50%, preferably from about 5% to about 25 and the ratio of detergent to builder salt is, preferably, in the range of 4:1 to 1:20; and, the composition, preferably, has a pH range of 8 to 1 1.

EXAMPLE VIII A suitable heavy duty detergent composition, providing a pH of 9.5, has the formulation:

Percent by wt.

Sodium dodecylbenzenesulfonate 23 Sodium tripolyphosphate 39 Sodium silicate solids 7 Sodium carboxymethylcellulose 1 Sodium sulfate 13 Monoethanolamide of coconut fatty acids 3 Water 8 Monohydrate of sodium N-chloro-N-(benzene-sulfonyl)-3-aminopropan-l-sulfonate 6 This product is particularly suitable for washing soiled white goods (e.g. table linen and bed linen) at normal washing machine temperatures (-175 F., especially about F.), and it is not necessary to use the high temperatures (200 F. to boiling) which are required for effective bleaching with sodium perborate as the bleaching agent. Substantially equivalent results are obtained if the sodium N-chloro-N-(benzene sulfonyl)-3-aminopropan-lsulfonate in the above formula is replaced by an equal weight of the corresponding N-chloro-N-(p-toluene-sulfonyl N-chloro-N- pchlorobenzenesulfonyl N-chloro-N- (methanesulfonyl or N-bromo-N- (p-toluenesulfonyl):3-aminopropan-1-sulfonates.

The :new N-halo compounds of the invention are, also, valuable as stain removing agents in abrasive hard surface cleanser compositions. They have very good bactericidal properties and can be used in the formulation of disinfectant and sanitizing compositions. For example, they can :be included in dishwashing compositions for use in automatic dishwashing machines, in which they serve both to -prevent protein spotting and as sanitizing agents.

Additional examples, further illustrating the utility of the invention herein, are as follows:

EXAMPLE IX Four dry granular bleaching compositions were made, using the following components:

Percent by wt. Sodium N-chloroN (benzenesulfonyl) 3 aminopropan-l-sulfonate 20 Water-soluble, inorganic alkaline salt 80 EXAMPLE X It is known in the art that detergent compositions which contain a combination of sodium tripolyphosphate (STP) and sodium salts of nitrilotriacetic acid (NTA) greatly enhance cleansing ability and maintenance of whiteness. (See Burton H. Gedge, US. Pat. 3,356,613, issued Dec. 5, 1967.) The novel N-halo compounds are suitable for use in such granular built detergents and serve to more effectively provide cleaning and whitening ability. Formulations of such granular detergents, containing the novel N- bromo and N-chloro compounds, have a pH range of 8 to 11 and are:

Formulation 1 A B C D Sodium linear dodecyl benzene sulf0nate 13. 3 10 Reaction product of SO; and C a-olefins neutralized with NaOH 20 Condensation reaction product of 1 mole of tallow alcohol and 10 moles of ethylene oxide (TEN) i e s NIA Sodium carboxymethyl cellulose 0 3 Sodium random octadecyl phosphonate. Sodium sulfate Sodium silicate (SiO;:Na O 1.6;1) Sodium salt of marine fatty acid. Sodium salt of tallow fatty acids Benzotrlazole Optical brightener (optional) Coloring (optional) Perfume (optional) t N-chloro-N-(ben1.encsulfonyl)\3-aminopropan-l-sulfonatc Water 7 7 7 Hal. Bal. Bal.

1 Figures in the columns are percentages by weight.

1 The range is variable and generally runs from 0.1% to 1% by weight.

I The range is variable and only traces are used, usually amounting to less than 0.5% by wei ht.

4 The range is varla le and generally runs from 0.1% to 1% by weight.

EXAMPLE XI The following is a granular detergent composition which contains a novel N-halo compound and the watersoluble organic alkaline salt, NTA:

Percent by wt. Sodium N-chloro N (benzenesulfonyl) 3 aminopropan-l-sulfonate 7 Sodium linear dodecylbenzene-sulfonate 7 NTA 50 Sodium carbonate 10 Sodium silicate 10 Water, bal.

' EXAMPLE XII An effective dry, granular, scouring cleanser composition, having bleaching and disinfecting characteristic; and

conveniently containing a novel N-bromo or N-chloro compound, is as follows:

(1) From about 0.1% to about 4%, by weight, of a novel N-chloro compound or from about 0.5% to about 9% of a novel N-bromo compound;

(2) From about 0.1% to about 10%, by weight, of a compatible water-soluble organic detergent;

(3) From about 2.5% to about 30%, by Weight, of a water-soluble alkaline detergency builder (organic or inorganic); and,

(4) From about 60% to by weight, of water-insoluble abrasive material.

The scouring cleanser formulations are most effective when used at a pH level of from 9 to 12. Examples of suitable detergents for use in these scouring cleanser compositions include those described in col. 5, lines 10- 58 of the specification herein; suitable water-soluble alkaline builder salts include those disclosed herein in col. 4, lines 6875, and col. 5, lines 18. Examples of waterinsoluble abrasives, suitable for use in the scouring cleanser compositions of the invention herein, include finely divided particulate siliceous abrasives such as silica, feldspar, pumice, volcanic ash, diatomaceous earth, bentonite, talc, and the like. A suitable particle size for the abrasive material ranges from about 0.03 mm. diameter to about 0.001 mm. diameter and finer.

An optional component of such scouring cleanser compositions is perfume, which if added, generally ranges from about 0.1% to about 1% by weight.

Suitable specific scouring cleanser compositions, containing novel N-chloro or N-bromo compounds, are as follows:

All figures are expressed in percentage by weight.

The specifications herein have disclosed that the novel N-bromo and N-chloro compounds can readily and conveniently be used in granular detergent, bleaching and scouring cleanser compositions. Such compositions are substantially dry, i.e., solid compositions which are dry to the touch and substantially devoid of uncombined moisture. Accordingly, the composition can contain components in a hydratable form (anhydrous or partially hydrated). Thus, the water-soluble inorganic alkaline salt used can be in the hydratable form, as well as the novel N-chloro and N-bromo compounds themselves, and no change in the effectivenesses or utility of the novel compounds occurs.

Therefore, what is claimed is:

1. N-halogenated compounds of the formula wherein M is an alkali metal selected from the group consisting of sodium, potassium, and lithium; X is chlorine or bromine; and R is selected from the group consisting of alkyl of from 1 to 18 carbon atoms; phenyl; and substituted-phenyl; the substituent of said substitutedphenyl being selected from the group consisting of alkyl of from 1 to 14 carbon atoms; C H OCH -NO,; chloro; bromo; COOH; SO H, CN, and N(CI-I 2. The compounds of claim 1 wherein X is chlorine and M is sodium.

3. The compound of claim 2 in which R is benzene.

4. The compound of claim 2 in which R is p-toluene.

5. The compound of claim 2 in which R is p-chlorobenzene.

6. The compound of claim 2 in which R is methane.

7. The compound of claim 2 in which R is dodecane.

8. The compounds of claim 1 wherein X is bromine, M is sodium, and R is p-toluene.

9. The method of making compounds of claim 1 which comprises (1) reacting an alkali metal sulfonamide having the formula wherein R and M have the same meanings as ascribed in claim 1, with 1,3-propane-sultone, and then (2) reacting the intermediate so formed and having the formula References Cited UNITED STATES PATENTS 2,694,727 11/1954 Cross et a1. 260508 DANIEL D. HORWITZ, Primary Examiner US. Cl. X.R.

260-465 R, 507 R, 501, 513 N; 252-98 @22 2? UNITED STATES PATENT OFFICE 1 CERTIFIQATE OF CORRECTION Patent No. 3,654, 348 Dated April 1972 I Inventor) Peter Robson and Frederick Edward Hardy It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

3 Col. 2 line 34, formula (1) SO -NH-Na" should be --R-SO NH-Na Col. 2, line 35, at the end of the line, "N" should be col. 8, line 40, (benzesulfonyl) should be (benzenesulfonyl) Signed and sealed this 10th day of October 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents Po-wso E (5/69) Patent No. 3,654; 8 Dated April 4, 1972 Inventor) Peter Robson and Frederick Edward Hardy It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2 line 34, formula 1) i SO NH-Na" should be C010 2, line 35,. at the end of the line, "N" should be Na Col. 8, line 40 (benzesulfonyl) should be (benzenesulfony'l) Signed and sealed this 10th day of October 1972.

(SEAL) Attest:

EDWARD MQFLETCHERJRQ ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

